Improvement in adding-machine



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THOMAS ROSSITER, OF NEW HAVEN, CONNECTICUT, ASSIGNOR OF ONE-HALF INTER- EST TO RUFUS H. SANFORD AND FRANK PRESCOTT, OF SAME PLACE.l

Letters Patent No. 93,350, dated Aug/ust 3, 1869.

IMPROVEMENT IN ADDING-MACHINE.

The Schedule referred to in these Lettere Patent and making part of the same.

.To all whom 'it may concern.-

Be it known that I, THOMAS Itcssrrnn, of New Haven, in the county of New Haven, and State of Connecticut, have invented a new and useful Adding- Machine; -and I do hereby declare that. the following is a full and exact description of the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon.

Figure 1 is a top or plan view of my improvement.

Figure 2 is a side view of the same.

Figure 3 is a partial section, -to more clearly show the position and operation of the disks.

Figure 4 isa longitudinal section of the same, ta-

ken through line y y.

Similar letters of reference, when they occur in the separate views, indicate like parts.

My invention relates to an improvement in a device for readily and accurately computing the sum of a column of figures, and consists of two registeringdisksor dials, operated by a shaft, connected to and revolved by an index-wheel, every revolution of which is recorded upon the said disks or dials, in a manner as will be hereafter described.

The object of my invention is to provide some siniple machine for adding figures, in order to take the place of the complicated and expensive machines now used for that purpose, as I propose to construct my improvement of such a size that it maybe joined to a lead-pencil, or conveniently carried in the pocket.

To enable others skilled in the art to make and use my invention, I will proceed to describe the construction and operation of' the saine with reference to the accompanying drawings.

A is the frame 0r case ofthe machine, provided with a socket, B, for the reception of the pencil.

C is an index-wheel, which is placed at one extremity of the machine. lt is held in position by means of the rod a, and is securely attached to and revolves withthe hollow shaft b.

In each of ten equal divisions of the circumference of this wheel is placed one ofthe numerical characters, commencing with zero, and extending, in regular order, to the figure nine.

In corresponding divisions upon the frame A (the first of which is filled by a star) are placed, in order, nine letters, A, B, C, D, E, F, G, H, I, the use of which involves a different method of computing from that when the index-wheel alone is used, and will hereafter be more fully described.

D is a registering-disk or dial, which is held upon the upper or fiat surface of the frame, in such a inanner as to allow its free revolution.

The periphery o this disk or Ydial is furnished with teeth or note es, to correspond with the ten equal divisions of its" upper surface, where figures or characters are placed, in order, as upon the indexwheel.

Y A pin, c, upon the shaft b, meshes into the said notches or teeth with every revolution of the shaft, and by this means the said disk D is operated. Y

E is another registering-disk or dial, similar to the disk D, but placed a little above it, and is 'operated by means of a pin, d, upon the said disk D, instead of directly from the shaft l).

Through the surface of the frame A, I place two holes or apertures, of any given size, each exposing one of the numbers on the disks D and E.

This completes the construction of my improvement.'

The operation is as follows: I

To prepare the machine for use, the zero on each disk must (by turning the index-wheel backward or forward, as the case may require,) be brought under the apertures. The zero upon the index-wheel C must also be placed opposite the star upon the frame, as shown in fig. 1.-

The work of yadding is commenced by revolving the index-wheel until the figure corresponding to the first figure in the column to be added is bronght'opposite the star upon the frame. The 'next figure in the column is then taken.

` If the sum of these two figures does not exceed ten, the number-upon the index denoting the said sum is placed opposite the star. If thc snm exceed ten, the ten is registered upon the disk D by the operation of the pin c and shaft b, and the figure denoting the excess is brought opposite the star, as before described. The next'figure in the column is added in thev same manner, and so on, until the column is finished.

If the sum of the columnishould exceed one hundred, the disk E is carried forward by the pin d,

upon the disk D, thus registering the hundred, while y the disk D again commences at zero, to register the tens.

Another methodof using my'machine, and one, in some cases, preferable, is as follows:

The machine must be first prepared for use in the same manner as before described.

Place the ligure upon the index-wheel correspond-A the letter opposite zero, and bring the next figure of The arrangement of the index-wheel C, hollow the column opposite it, as before, and so on, until the shaft b, registering-disks D and E, actuated by the column is finished. pin c, contained within the case A, constructed as In both these methods, the answer will be found shown und described. by referring 'to the apertures, counting the number This specification signed and witnessed, this 26th upon the diskzE as hundreds, that upon the disk D as day of Mey, 1869. tens, and the one opposite the star upon the index- THOMAS ROSSITER. wheel as units.

Having thus fully described my invention, Witnesses: lVhat I claim as new and useful, and desire t0 se- NVM. OLMSTEAD,

cure by Letters Patent, is- GEO. H. LARNED. 

